Field of the Invention
The present invention relates to a surgical clip and the apparatus for manufacturing that clip. More particularly, the present invention concerns a novel surgical clip design to be applied to a vein, artery or other blood vessel during surgery to constrict or close the vessel at a specific location so that the vessel may be severed or cut without subsequent loss of blood.
Ligation or occlusion of veins, arteries or blood vessels has been a necessary part of surgical procedures for many years. Initially, surgeons used thread or suture material to tie a blood vessel prior to severing the vessel. This procedure required both skill and time on the part of the surgeon to properly close the vessel. In many instances, assistance of a nurse or attending surgeon was necessary and typically, a severed blood vessel would require closure on both sides of a severance site before actual cutting could take place. The advent of surgical clips and clip appliers has greatly enhanced this procedure.
Many factors are critical to the design of a surgical clip. Among these, it is important that the clip not slip or become dislodged from a blood vessel after the blood vessel is severed. In that instance, blood will immediately begin flowing into the surgery site through the unclamped vessel requiring the operation be delayed while the critical vessel is located and reclamped. Depending on the type and location of the surgery, locating the vessel may be difficult and the time delay could cause medical complications to the patient.
Similarly, a clip must be designed to fully and completely close about a vein, artery or blood vessel and completely stop the flow of blood through these pathways. A clip which does not completely occlude the flow of blood is useless for its intended function. In addition, if the clip is of such a size or is designed in such a manner that during deformation about a vessel a portion of the vessel is allowed to extend beyond the tips of the clip legs, the clip will obviously not completely restrict the flow of blood and similar serious problems could arise. Consequently, besides insuring that the vessel is completely trapped within the clip, the clip must be designed such that when it is completely formed about a vessel the flow of blood through the vessel is completely precluded.
Generally, surgical clips are U-shaped or V-shaped members having two legs joined at an apex or crown portion and spaced apart at the opposite end. Typically, the inside surface of the clip legs are deformed in some manner, such as having varying types of holes, slots or grooves, in an attempt to improve the occluding functions of the clip after the clip has been deformed about a blood vessel. Instead of achieving this desired end result, many prior art designs actually promote the lateral slippage or opening of a clip after it has been applied about a vessel.
Within these design considerations, care must be taken to avoid employing sharp edges of any kind which might cause the vessel to be cut or severed by the clip during formation. The design of many prior art clips promote inconsistent deformation which in combination with the shape of the clip can cause the clip to sever or damage the blood vessel thereby requiring additional clips be applied to restrict the flow of blood and, subsequently, the damaged vessel be repaired.
Not only must clips be made uniformly so that each and every clip will consistently deform in the same manner, but the nature of clip appliers for applying and deforming clips has progressed and added new demands to the design of a surgical clip. Originally, clip appliers were scissors or pliers type instruments in which a single individual clip was manually inserted between the jaws of the instrument and then subsequently deformed about a blood vessel. As a result, the exact design of the clip with respect to its fit within the clip aplier was not critical. Clip appliers are now available which house clip cartridges or magazines containing 35 or more individual clips. Consequently, not only must each of these individual clips perform in exactly the same way but the design of the clip now must also account for storage and advancement of the clip in the many different clip cartridges and magazines employed in multiple count clip appliers.
For example, in some multiple count clip apliers the clips are abuttingly arranged in a single forward facing row wherein an advancing force is applied to the last clip in the row and each clip pushes or advances the clip in front of it. Under these conditions the design of the clips must act to maintain the row of clips in alignment. However, if the legs of a clip are different in length, as can easily happen under conventional manufacturing methods, the clip will not properly align with the next forwardmost clip. This will ultimately cause the entire row to become unaligned as the clips are pushed forward in the clip magazine. In addition, if the tip of each leg is not shaped to receive and engage the crown of a clip, the row of clips similarly could become unaligned. This is the case with conventional clips where the crown of the clip is angled with respect the flat forward tips of the legs.
These problems are resolved by providing a clip with a uniform clip stack length and a modified leg tip design. Clip stack length is defined as the distance between the chamfered clip leg tips on abutting clips measured between the point at which the beveled surface joins the inside surface of the clip. By maintaining a uniform clip stack length for each clip and by modifying the tip of the clip leg to cooperate with the shape of the clip crown, the row of clips will become self-aligning and advancement of the row of clips will be enhanced. Moreover, the availability of clips with a uniform stack length will allow clip applier manufacturers to forget the problems of clip feed inherent with the use of clips having varying clip lengths. The apparatus for manufacturing the clip of the present invention insures the production of clips with a uniform stack length and a leg tip configuration adapted to cooperate with the crown or apex of the clip.
In other types of clip magazines the design of the clip is not a factor in the feed or advancement of the clips. These types of magazines or cartridges employ a complex arrangement of teeth or similar devices which separately hold and advance the clips without any contact between clips or vertically stack the clips one on top of another. The clip of the present invention will function in these cartridges as well.
The present clip is designed with a longitudinal center channel or groove and a series of transverse notches which, when the clip is deformed, cooperate to create a clip which prevents the flow of blood and further prevents lateral and longitudinal slippage on the vessel. In addition, the apparatus for manufacturing the clip insures reliable and uniform deformation of each and every clip in such a manner that the clip will not damage or sever a blood vessel and will produce a clip with a uniform stack length which can be used in almost any cartridge or magazine of a multiple clip applier employing standard surgical clips.